Cogset assembly for a bicycle

ABSTRACT

A bicycle hub assembly comprises a shaft, a first load bearing adjacent said shaft, a hub main body surrounding said shaft, and a cogset. The cogset can define an inner surface, and the inner surface can define a seat configured to receive the first load bearing. Further, the inner surface can define an opening of variable size. The cogset can also define an inner end and an outer end, and the opening can generally increase in size from the outer end to the inner end.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of U.S. patentapplication Ser. No. 12/019,495, filed Jan. 24, 2008, and entitled“COGSET ASSEMBLY FOR A BICYCLE”, the entirety of which is herebyexpressly incorporated by reference herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The inventions described herein generally relate to apparatuses fordriving bicycles.

2. Description of the Related Art

The related art includes bicycle drives such as gears and sprockets,connected by chain to pedals or some other power source.

SUMMARY OF THE INVENTION

In accordance with some embodiments of a cogset assembly for a bicycle,a bicycle hub assembly comprises a shaft, a first load bearing adjacentsaid shaft, a hub main body surrounding said shaft, and a cogset. Thecogset can define an inner surface, and the inner surface can define aseat configured to receive the first load bearing. Further, the innersurface can define an opening of variable size. The cogset can alsodefine an inner end and an outer end, and the opening can generallyincrease in size from the outer end to the inner end.

In some embodiments the cogset can further define two mounting portions.The first mounting portion can define a smaller open cross-section thanthe second mounting portion, and can cooperate to rotatably mount thecogset on a shaft. The second mounting portion can cooperate to mountthe cogset on a hub assembly.

Further, in some embodiments the shaft can define an outer surface thatcan define a smaller diameter portion. The smaller diameter portion canbe adjacent an outer end of the cogset. A larger diameter portion can beadjacent an inner end of the cogset. The shaft can also define a smallerdiameter portion positioned opposite the outer end of the cogset. Theshaft can be substantially composed of carbon fiber, aluminum, steel,similar materials, or mixes thereof. The shaft can also have a diametergreater than 15 mm.

Further, some embodiments can comprise a ratchet mounted on the hub mainbody. Similarly, in some embodiments a ratchet portion can be mounted onthe cogset, corresponding to the ratchet mounted on the hub. In otherembodiments, a ratchet assembly can be mounted on the cogset.

In some embodiments, a bicycle hub assembly can comprise a hub mainbody. The hub main body can be surrounded by a bushing. A cogset can berotatably supported by the bushing. The cogset can further define aninner surface, and the inner surface can define an opening of variablesize. Further, the opening can generally increase in size from an outerend to an inner end, each defined by the inner surface of the cogset.The hub assembly can further comprise a ratchet mounted on the hub mainbody, and a ratchet portion mounted on the cogset. In other embodiments,the hub assembly can comprise a ratchet assembly mounted on the cogset.

In some embodiments, a bicycle hub assembly can comprise a hub main bodydefining an axis. The bicycle hub assembly can further comprise a cogsetsurrounding a portion of the hub main body. Further, the cogset canextend axially from the hub main body and be rotatable with respectthereto. The cogset can further define an inner surface, said innersurface defining an opening of variable size. Further, the opening cangenerally increase in size from an outer end to an inner end, eachdefined by the inner surface of the cogset. The hub assembly can alsocomprise a ratchet mounted on the hub main body. The hub assembly canfurther comprise a ratchet portion mounted on the cogset. In otherembodiments, the hub assembly can comprise a ratchet assembly mounted onthe cogset.

In some embodiments, a bicycle hub assembly can comprise a bicycleshaft, a first load bearing adjacent the shaft, a hub main bodysurrounding the bicycle shaft, and a cogset. The cogset can bepositioned substantially directly against the first load bearing.Similarly, the cogset can be positioned within a half (½) millimeter ofthe load bearing.

In some embodiments, a cogset can comprise an inner surface comprising aplurality of ratchet teeth. The cogset can further comprise a pluralityof cogs and a portion for receiving a bearing assembly along the innersurface. The inner surface can have variable size along the axis of thecogset. Further, the inner surface can generally increase in sizemonotonically from one end of the cogset to another. The cogset canfurther include at least one cog with cog size less than 11. The cogsetcan also comprise an outer surface, said outer surface comprising cogssubstantially formed from at least two distinct materials. At least oneof said materials can be titanium.

In some embodiments a cogset can comprise a plurality of cogs and aninner surface comprising a spline portion. The inner surface cancomprise variable size along the axis of the cogset and a portion forreceiving a bearing assembly. The inner surface can generally increasein size monotonically from one end of the cogset to another. The cogsetcan further include at least one cog with cog size less than 11 teeth.The cogset can also comprise an outer surface comprising cogssubstantially formed from at least two distinct materials. At least oneof said materials can be titanium.

For purposes of this summary, certain aspects, advantages, and novelfeatures of the invention are described herein. It is to be understoodthat not necessarily all such advantages may be achieved in accordancewith any particular embodiment of the invention. Thus, for example,those skilled in the art will recognize that the invention may beembodied or carried out in a manner that achieves one advantage or groupof advantages as taught herein without necessarily achieving otheradvantages as may be taught or suggested herein.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts a bicycle with one embodiment of a cogset and hubassembly.

FIG. 2A depicts a perspective view of a cogset and hub assembly.

FIG. 2B depicts an exploded view of the cross-sectioned cogset and hubassembly of FIG. 2A.

FIG. 3A depicts a side view of the cogset and hub assembly mounted on abicycle.

FIG. 3B depicts a side cross-sectional view of the cogset and hubassembly of FIG. 3A.

FIGS. 4 and 5 depict axial cross-sectional views of the cogset and hubassembly of FIG. 3A along 4-4 and 5-5, respectively.

FIG. 6 depicts an exploded view of a cogset assembly.

FIG. 7A depicts a perspective view of an alternative embodiment of acogset and hub assembly.

FIG. 7B depicts an exploded cross-sectional view of the cogset and hubassembly of FIG. 7A.

FIG. 8A depicts a side view of a cogset and hub assembly of FIG. 7A.

FIG. 8B depicts a side cross-sectional view of the cogset and hubassembly of FIG. 8A.

FIG. 9 depicts an axial cross-sectional view of the cogset and hubassembly of FIG. 8A along 9-9.

FIG. 10 depicts an exploded view of a cogset assembly.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

A number of objectives are presented in the context of bicycle design.It is generally desirable to provide a bicycle that is simultaneouslylight, reliable, capable of both high and low gear ratios, andcomprising minimal friction or loss, as well as other objectives.Material strength is often proportional to material size and weight, andthus lightness and reliability often present conflicting objectives.

The disclosure herein describes a cogset assembly for a bicycle. Thedisclosure herein additionally describes a hub assembly for a rearbicycle wheel. The disclosure herein additionally describes combinationsof cogset and hub assemblies.

FIG. 1 depicts a bicycle 1 with a cogset and hub assembly 6. The bicycle1 can comprise a frame 11, pedals 3, pedal sprocket 5, chain 4, cogsetand hub assembly 6, and rear wheel 2. The frame 11 can comprise stays 12that can connect a rear wheel 2 to the main portion of the bicycle frame11. The rear wheel 2 can be driven by pedals 3 via a chain 4. The linksof the chain 4 can be configured to interact with the pedal sprocket 5,which causes the chain 4 to rotate upon the rotation of the pedals 3.The chain 4 can further interact with a cogset and hub assembly 6 tocause the cogset and hub assembly 6 to rotate, thus also rotating therear wheel 2 as discussed below. The rear wheel 2 may further comprise aderailleur 7 capable of moving the chain 4 between a plurality ofsprockets. Additionally, the rear wheel 2 may comprise a plurality ofspokes 9 for improving the structural integrity and strength of the rearwheel.

FIGS. 2A, 3A depict a perspective view and a side view of one embodimentof the cogset and hub assembly 6. The cogset and hub assembly 6 maycomprise a shaft 36, a hub main body 40, and a cogset 20. The cogset 20may comprise a plurality of cogs 21 shaped to engage the chain 4.Through the cogs 21, the rotation of the chain 4 can cause the rotationof the cogset 20. The rotation of the cogset 20, through means discussedbelow, can in turn cause the rotation of the hub 40. The rotation of thehub 40, through the flanges 45 and spokes 9, can cause the rotation ofthe rear wheel 2. End caps 60, 61 can further rotate with the cogset 20and hub 40. In other embodiments the end caps 60, 61 can rotateindependently of the cogset 20 and/or hub 40, or they can remainstationary.

Referring to FIGS. 2B, 3A, and 3B, the cogset 20 can be located near adriven end 100 of the cogset and hub assembly 6 and the large end cap 61can be located near a free end 101 of the cogset and hub assembly 6. Thecogset 20 can be connected to a hub 40 at a hub facing end or inner end23 of the cogset 20 and a sprocket facing end or first end 41 of the hub40. The hub 40 further comprises a free end or second end 42 oppositethe first end 41. At the free end 42 the hub 40 can connect to a largeend cap 61 that can in turn connect to a connection means 70 forattaching the cogset and hub assembly 6 to the frame 11 via the stays 12(not pictured in FIG. 3B). Alternatively, the hub 40 can connectdirectly to a connection means 70 (not pictured in FIG. 3B). As shown,the hub 40 further comprises two radially extending flanges 45, whichcan connect to a plurality of spokes 9 (shown in FIG. 1). The flanges 45can be provided a set distance apart. For purposes of this application,“free end” is a broad term used broadly to distinguish the driven end100, 41 and is not intended to mean that there are no items attached toor covering the free end 101, 42.

The cogs 21 are provided radially and can be grouped into circularsprockets. The cogs 21 on a sprocket can describe a radius or cog sizewhich, in conjunction with the analogous radius or cog size of the pedalsprocket 5, determines a gear ratio.

The cogset 20 and hub 40 can be mounted on a shaft 36. The shaft 36 maycomprise a shaft main body 30, a driven end cap 60, and a free end cap61. In some embodiments, use of the end caps 60, 61 can be advantageousto provide a means of sealing the driven end 22 of the cogset 20 and theends of the shaft main body 30. Further, in some embodiments, the use ofend caps 60, 61 may provide for greater ease of manufacture and/orweight reduction advantages. Alternatively, in some embodiments, theshaft can comprise a single piece and/or one or both of the end caps 60,61 can be eliminated.

The shaft 36 can be mounted by way of connection means 70 to stays 12.The distance between the stays 12 can define an assembly length L_(A)along the axis of the cogset and hub assembly 6. As best shown in FIG.3A, the length of the shaft 36 may span the entire assembly lengthL_(A). In addition, the shaft 36, including the end caps 60, 61, alongwith the hub 40 and the cogset 20 may span the entire assembly lengthL_(A).

As shown, the rear wheel cogset 20 can comprise a plurality of sprocketswith different radii or cog sizes. Similarly, the pedal sprocket 5 canalso comprise a plurality of sprockets with different radii or cogsizes. A greater number of sprockets can comprise a greater portion ofthe assembly length L_(A). Further, the cogs on the sprockets can be aset distance apart, both on a given sprocket and between sprockets. Thecogs on adjacent sprockets can be at least a set distance apart so as toallow space for the chain 4 to surround each cog without causinginterference with the cogs of an adjacent sprocket. Further, the cogs ona single sprocket can be a set radial distance apart on each sprocket soas to accommodate a single chain 4 designed to interact with all thesprockets of the cogset 20.

As depicted in 3A, the cogset and hub assembly 6 may be connected to twostays 12. The stays 12 may comprise generally forked shapes such thatthe cogset and hub assembly 6 can slide into position. The shaft 36 canthen be rigidly held between the stays 12 by a connection means 70 sothat the cogset and hub assembly 6 is secured to the bicycle 1. Saidconnection means 70 can comprise nuts and bolts, a quick-release, or anyother means for creating a substantial force between the cogset and hubassembly 6 and the stays 12, such that frictional forces hold theassembly in place. The stays 12 can also comprise hooks, enclosures, orany other means to hold the cogset and hub assembly 6 in place.

Referring to FIGS. 2B, 3A and 3B, the hub 40 comprises an inner surface48 defining an interior hub opening 81 configured to receive a shaft 36and allow rotation of the hub relative to the shaft. Friction betweenthe shaft 36 and hub 40 can be reduced with hub bearings 31, 32.Alternatively, bushings, lubricants, low-friction surfaces, rollers, orthe like can also be used.

Referring to FIG. 2B, the cog-facing end 41 of the hub 40 can comprise asplined portion 49 configured to interact with the spline of a firstaxial ratchet portion 50 such that the rotation of the first axialratchet portion causes an equivalent rotation of the hub and vice versa.The cogset 20 may define a splined portion 24 configured to interactwith a second axial ratchet portion 51. The first axial ratchet portion50 and the second axial ratchet portion 51 may each have teeth 56, 57,respectively. The teeth 56 of the first axial ratchet portion 50 may beaxially facing and configured to interact with the desirably axiallyfacing teeth 57 of a second axial ratchet portion 51. These axialratchet portions 50, 51 can be biased together by a pair of springs 52between which the axial ratchets are provided. When the axial ratchetportions 50, 51 are biased together their teeth 56, 57 interact suchthat the axial ratchets can rotate relative to one another in only onedirection. Rotation of one axial ratchet in the opposite direction,while compelled against the other axial ratchet, will cause said otheraxial ratchet to also rotate in said opposite direction. By way of thesplines, the ratchets 50, 51 can thus force similar rotationalproperties between the hub 40 and the cogset 20. The axial ratchets 50,51 may rotate around the shaft 36 directly, or be spaced somewhat fromthe shaft 36 as shown here via a bushing 53. It will be clear from thedescription herein that other methods can be used to reduce frictionbetween the axial ratchets 50, 51 and the shaft 36.

The cogset 20 can be configured and/or equipped to rotate about andmount onto the hub 40 and/or the shaft 36. The cogset 20 may mount ontothe hub 40 at the cogset inner end 23 or, as shown, spaced somewhatoutward from its inner end. In various embodiments, the cogset may bemounted onto the hub spaced at least ¼ inch, ½ inch, ¾ inch, 1 inch, 1¼inch, and 1½ inch from the inner end 23 of the cogset 20. The cogset 20may be mounted on the hub spaced no more than ¼ inch, ½ inch, ¾ inch, 1inch, 1¼ inch, 1½ inch, 1¾ inch and 2 inches from the inner end 23 ofthe cogset 20. Typically, the inner end of the cogset 20 will be definedby the innermost cog of the cogset. Typically, this innermost cog willbe the largest diameter cog of the cogset 20, but alternativeconfigurations are possible, such as providing the largest diameter tothe outermost cog. In various embodiments the sprocket facing end 41 ofthe hub 40 will extend into the cogset 20 at least ¼ inch, ½ inch, ¾inch, 1 inch, 1½ inch, 1¾ inch, 2 inches, 2¼ inches, 2½ inches, 2¾inches or 3 inches. A bushing 43 can be provided between the hub 40 andthe cogset 20 to facilitate rotation and reduce friction between them.Other friction-reducing elements can be used. Similarly, the cogset 20can mount on the shaft 36 at the outer end 22, as depicted here by wayof cogset bearing 35. The cogset 20 can thus act as part of the hub 40.

As discussed above, at the ends 100, 101 of the cogset and hub assembly6 can be provided end caps 60, 61. A short end cap 60 can be providednear the cogset 20 and a long end cap 61 can be provided near the hub40. Thus, the spokes 9 connecting the hub 40 and the wheel 2 can bepositioned near the center of the space between the stays 12. In someembodiments, the cogset 20 and the long end cap 61 may be shorter,allowing for a longer hub 40 or shorter assembly length L_(A). Providinga longer hub 40 may be undesirable due to increased weight. Similarly,providing a shorter assembly length L_(A) may be desirable by providinga shorter moment arm on the shaft 36. It will be clear from thedescription herein that other factors may be considered in choosing theassembly length L_(A) and the size of the hub 40.

In other embodiments the spokes 9 may be positioned substantially towardthe free end 101 or to the driven end 100 of the assembly length L_(A).When the spokes 9 are positioned substantially toward the free end 101,more space can be available for the sprocket 20 and hub 40. The end caps60, 61 can comprise, either integrally or in a separate part(s),connecting means 70 such as a nut and bolt to rigidly attach the cogsetand hub assembly 6 to the stays 12.

Referring to FIG. 3B, the cogset 20 may mount directly, or substantiallydirectly, onto the hub 40 and the shaft 36 by way of a bushing 43 andcogset bearing 35 respectively. Thus, in some embodiments, a separatesprocket carrier or other intermediary element is not necessary.Additionally, the cogset 20 can interact directly, or substantiallydirectly, with the second axial ratchet portion 51 and the hub 40without an intermediary element. As further shown, the end caps 60, 61can provide a substantially complete seal, preventing the contaminationof the bearings 31, 35, shaft 36, hub 40, cogset 20, or other elementsof the cogset and hub assembly 6. As further shown, in some embodimentsno lock ring is necessary to secure a free wheel body separate of thecog set.

Referring to FIGS. 2B and 3B, the cogset 20 may comprise an innersurface 80 of variable size. Said inner surface 80 may define across-sectional opening which increases in size from the outer end 22 tothe inner end 23 generally monotonically, substantially monotonically,or in some other way. The profile of the diameter of the inner surface80 of the cogset 20 may generally match the profile of the diameter ofthe cogs of the cogset 20.

Extending inward from the inner surface 80 may be a mounting portion orpost 28. As shown, the mounting post 28 can provide the interfacebetween the cogset 20 and the hub 40, via the bushing 43. The mountingpost 28 may extend angularly completely around the bushing 43,comprising a shape similar to a disc. Alternatively, the mounting post28 may comprise a plurality of posts comprising spoke-like structures.Further, the position of the mounting post 28 along the axis of thecogset and hub assembly 6 may vary. As shown in FIG. 3B the mountingpost 28 is positioned within the interior of the cogset 20. In otherembodiments the mounting post 28 can sit further toward the hub facingend 23 of the cogset 20 or further toward the outer end 22, near theratchets 50, 51. As to be discussed further below, varying the positionof the mounting post 28 can allow greater flexibility in the design ofthe cogset and hub assembly 6, such as allowing for larger ratchets 50,51.

With respect to FIG. 3B, the cogset 20 and hub 40 can further compriseseats 29, 46, 47 for the bearings 31, 32, 35. The cogset 20 can comprisea seat 29 along its interior to receive a cogset bearing 35 that canallow rotation about the shaft 36. Similarly, the hub 40 can comprisehub bearing seats 46, 47 to receive hub bearings 31, 32 that can allowrotation about the shaft 36. In one embodiment, the cogset 20 may definean outermost drive end cogset bearing seat 29 which receives cogsetbearing 35. In some embodiments, the hub 40 can comprise a free endbearing seat 46 for receiving a free-end bearing 31. In someembodiments, the hub 40 can define a driven end hub bearing seat 47 forreceiving a driven end hub bearing 32. In some embodiments, asillustrated, the driven end hub bearing 32 may be spaced outward fromthe driven end hub flange 45 of the hub 40 and may be spaced outwardfrom the inner end 23 of the cogset 20. In particular, the driven endbearing seat 47 and driven end hub bearing 32 may be positioned at least¼ inch, ½ inch, ¾ inch, 1 inch, 1¼ inch, 1½ inch, 1¾ inch and 2 inchesfrom the inner end 23 of the cogset 20. In various embodiments, thedriven end hub bearing seat 47 and driven end hub bearing 32 may bemounted on the hub spaced no more than ¼ inch, ½ inch, ¾ inch, 1 inch,1¼ inch, 1½ inch, 1¾ inch and 2 inches from the inner end 23 of thecogset 20. In various embodiments the sprocket facing end 41 of the hub40 will not extend beyond the driven end hub bearing 32 or will extendbeyond the driven end hub bearing 32 at least ¼ inches, ½ inch, ¾ inch,1 inch, 1½ inch, 1¾ inch, 2 inches, 2¼ inches, 2½ inches, 2¾ inches or 3inches. The driven end hub bearing 32 and driven end hub bearing seat 47may be of variable size, material, and fit depending on the loads thatmust be born while supporting the weight of the bicycle 1 and its cargo,and during rotation.

The free end hub bearing seat 46 and the free end hub bearing 31 maycomprise similar positions relative to the free end 42 of the hub 40.For example, the free end hub bearing seat 46 and free end hub bearing31 may be positioned at least ¼ inch, ½ inch, ¾ inch, 1 inch, 1¼ inch,1½ inch, 1¾ inch, 2 inches, 2¼ inches, 2½ inches, 2¾ inches, and 3inches from the free end 42 of the hub 40. In various embodiments, thefree end hub bearing seat 46 and free end hub bearing 31 may be mountedon the hub spaced no more than ¼ inch, ½ inch, ¾ inch, 1 inch, 1¼ inch,1½ inch, 1¾ inch, 2 inches, 2¼ inches, 2½ inches, 2¾ inches, and 3inches from the free end 42 of the hub 40. Further, the free end hubbearing seat 46 and the free end hub bearing 31 may similarly comprisesize, material, and fit depending on the loads that must be born whilesupporting the weight of the bicycle 1 and its cargo, and duringrotation.

The cogset bearing seat 29 and cogset bearing 35 may comprise similarpositions relative to the driven end 23 of the cogset 20 and the stay 12on the driven end 100 of the cogset and hub assembly 6. For example, thecogset bearing seat 29 and cogset bearing 35 may be positioned no morethan ¼ inch, ½ inch, ¾ inch, 1 inch, 1¼ inch, 1½ inch, 1¾ inch and 2inches from the driven end 23 of the cogset 20. In various embodiments,the cogset bearing seat 29 and cogset bearing 35 may be mounted on thecogset spaced no more than ¼ inch, ½ inch, ¾ inch, 1 inch, 1¼ inch, 1½inch, 1¾ inch and 2 inches from the driven end 100 of the cogset and hubassembly 6. Further, the cogset bearing seat 29 and the cogset bearing35 may similarly comprise size, material, and fit depending on the loadsthat must be born while supporting the weight of the bicycle 1 and itscargo, and during rotation.

The bearing seats 29, 46, 47 and the bearings 31, 32, 35 can have a widestance. For example, the cogset and driven end hub bearing seats 29, 47and/or the cogset and driven end hub bearings 32, 35 can be positionedat least outside of the hub flange 45 and/or inside the cogset 20. Thecogset and free end hub bearing seats 29, 46 and/or the cogset and freeend hub bearings 31, 35 can be spaced apart at least two-thirds thecombined length of the cogset 20 and hub main body 40. The driven endand free end hub bearing seats 45, 46 and/or the driven end and free endhub bearings 31, 32 can be spaced apart at least ½ the combined lengthof the cogset 20 and hub main body 40.

In some embodiments the cogset and hub assemblies 6 described herein maycomprise a wide variety of materials, sizes, shapes, and orconfigurations. Because in some embodiments the cogset 20 can mountdirectly or substantially directly onto the hub 40 and/or shaft 36without an intermediary element such as a sprocket carrier, the cogset'sinner diameter can be approximately equal to the outer diameter of thehub 40 and/or the shaft 36. Thus, in some embodiments the cog size maybe substantially smaller while mounted on a shaft 36 compared to priorart cogset and hub assemblies. For example, a cogset and hub assembly 6mounted on a shaft 36 may comprise at least one sprocket comprising aninner diameter less than 1%, 2%, 3%, 5%, 7%, 10%, or 15% greater thanthe diameter of the shaft 36 upon which the cogset and hub assembly 6 ismounted. Further, the shaft 36 may comprise a diameter not less than 1inch, 1½ inch, 1¾ inch, 2 inches, 2¼ inches, 2½ inches, 2¾ inches, 3inches, 15 mm, 16 mm, 17 mm, 18 mm, 19 mm, or 2 cm. Alternatively, theshaft may have an external diameter less than 1 inch, ⅞ inch, ¾ inch, ⅝inch, or ½ inch. The shaft 36 may further comprise a lighter materialsuch as carbon fiber, steel, aluminum, plastics, titanium, and the like.The cogset 20 may further be mounted directly or substantially directlyonto load bearings which similarly mount onto the hub 40 and/or shaft36.

Further, the size of the load bearings 31, 32, 35 may be altered. Asshown in FIG. 3B, the bearings 31, 32, 35 can be positioned relativelywide along the axis of the cogset and hub assembly 6. The load bearings31, 32, 35 can comprise a bearing diameter of approximately 9/16 inch.Alternatively, the load bearings can comprise a bearing diameter greaterthan 9/16 inch. Further, the balls in the load bearings 31, 32, 35 maycomprise a ball bearing diameter less than 1/32 inch, 1/64 inch, 1/128inch, 3/128 inch, 0.8 mm, 0.6 mm, 0.4 mm, or 0.2 mm. Further, the loadbearings 31, 32, 35 and their respective balls may comprise differentsizes.

Further, the bearings 31, 32, 35 and bearing seats 29, 46, 47 can bepositioned at varying points along the axis of the cogset and hubassembly 6. For example, the cogset bearings 35 can be positioned within1%, 2%, 3%, 5%, 7%, or 10% of the assembly length L_(A) from the drivenend 100 of the cogset and hub assembly 6. Similarly, the hub bearings31, 32 may be positioned within 1%, 2%, 3%, 5%, 7%, or 10% of theassembly length L_(A) from the corresponding ends of the hub 40.

Further, the ratchet portions 50, 51 used may comprise a larger size.For example, the axial ratchet portions 50, 51 depicted in FIG. 3B maycomprise a larger size, in this instance by providing them furthertoward the inner end 23 of the cogset 20 and similarly providing themounting post 28 further toward the inner end 23 of the cogset 20. Theratchet portions 50, 51 may comprise 18 teeth 56, 57 with a ratchetsurface area of 0.22 square inches. As can be seen from FIG. 3B, amplespace can be provided within the cogset and hub assembly 6 depicted formuch larger axial ratchet portions 50, 51. For example, the ratchetportions 50, 51 may comprise more than 18 teeth 56, 57 and/or have aratchet surface area of greater than 0.22 square inches. Further, theaxial ratchet portions 50, 51 can, comprise lighter materials, a greaternumber of teeth per degree of rotation, and further design changes.

Further, the assembly length L_(A) can be distributed varyingly betweenthe parts of the cogset and hub assembly 6. For example, the hub 40 canbe made shorter or be more substantially overlapped by the cogset 20.Further, the cogset 20 may be within ¼ inch, ½ inch, ¾ inch, 1 inch, 1½inch, 1¾ inch, 2 inches, 2¼ inches, 2½ inches, 2¾ inches or 3 inches ofthe spokes 9. Further, the axis length L_(A) may be divided, forexample, such that the large end cap generally comprises 10%, 20%, 30%,or 40% of the axis length, the distance between the flanges 45connecting to the spokes generally comprise 10%, 20%, 30%, 40%, 50%,60%, or 70%, and/or the cogset generally comprises 10%, 20%, 30%, or 40%of L_(A).

Further flexibility can be provided by varying the distance between cogson adjacent sprockets of the cogset 20. For example, increasing thedistance between cogs on adjacent sprockets can allow lighter materialsto be used. Alternatively, decreasing the distance between cogs onadjacent sprockets can allow a greater number of sprockets on the cogset20. In some embodiments the cogset 20 may comprise greater than 9, 10,11, 12, 13, 14, or 15 sprockets.

As shown in FIG. 4, the cogset 20 can mount almost directly onto the hub40, with only a bushing 43 in between to reduce friction. The hub 40 canin turn mount onto the shaft 36 with a set of hub bearings 31, 32 toreduce friction. As shown in FIG. 5, the cogset 20 can mount almostdirectly onto the shaft 36, with only cogset bearings 35 in between toreduce friction. In other embodiments it may be desirable to distancethe cogset 20 from the cogset bearings 35. This distance may beapproximately 1/32 inch, 1/64 inch, 1/128 inch, or 1/256 inch.Similarly, the distance may be no more than ½ mm.

Referring to FIG. 6, one embodiment of the cogset 20 can comprise twopieces 25, 26 attached by cogset spline portions 18 to causeco-rotation. The pieces can be further connected by screws, welds,adhesives, or any other connecting means known in the art or combinationthereof. The first cogset 25 can comprise a distinct material from thesecond cogset 26. For example, the first cogset 25 can comprisealuminum, titanium, steel, and/or carbon fiber. The second cogset 26 cancomprise steel and/or titanium. Generally, the second cogset 26 cancomprise a heavier and/or stronger material than the first cogset 25.Further, the second cogset 26 may connect with the cogset and hubassembly 6 via the first cogset 25. The second cogset 26 may comprisecog sizes from 11 to 14. The first cogset 25 may comprise cog sizes from15 to 20. In other embodiments, the first cogset may comprise cog sizeslower than 11 while the second cogset may comprise cog sizes greaterthan 26. As shown, the first cogset 25 may further comprise a splineportion 24 within its interior.

FIGS. 7A and 8A depict a perspective view and a side view of analternative embodiment of a cogset and hub assembly 6′. As shown in FIG.7A, the assembly 6′ can comprise a first ratchet portion such as aplurality of radially extending pawls 54 configured to interact with asecond ratchet portion, such as a radially facing ratchet portion of acogset 20′. Referring to FIG. 7B, the shaft main body 30′ may compriselarger and smaller diameter portions 33, 34. The larger diameter portion34 of the shaft main body 30′ may be associated with a larger diameterportion of the hub 40′. Similarly, the driven end hub bearing 32′corresponding to said larger diameter portion 34 may also be larger. Theshaft main body 30′ may further comprise smaller diameter portions 33 oneither end of the larger diameter portion 34, which can interface withthe outer end 22 of the cogset 20′ and/or the second end 42 of the hub40′.

As shown in FIG. 7B, the hub 40′ may further comprise a pawl receivingportion 44. The pawl receiving portion 44 may be configured toaccommodate at least one pawl 54 and a pawl spring 55. The pawls 54 mayrotate about a connection with the hub 40 and can be compelled to rotateoutward by the pawl spring 55. Alternatively, multiple springs may beused. The pawls 54 and the pawl spring 55 can be configured to interactwith a ratchet portion 27 of the cogset 20′ such that the cogset 20′ mayrotate in only one direction relative the pawls 54. Upon rotation of thecogset 20′ in the other direction, the interaction between the pawls 54and the ratchet portion 27 can cause the hub 40′ to also rotate in saidopposite direction.

Referring to FIG. 8B, the shaft 36′ can comprise a larger diameterportion 34 near the pawls 54 of the hub 40′. As further shown, thelarger diameter portion 34 may be accommodated by larger diameterportions of the hub 40′ and cogset 20′. If desirable, the shaft size maycomprise a different diameter profile, such as a larger diameter alongthe full length of the hub 40′.

In this embodiment, the mounting post 28′ can be substantially shorterto accommodate the reduced clearance between the general profile of theinner surface 80 of the cogset 20′ and the shaft 36′. The mounting post28′ may comprise different shapes and positions as discussed above withmounting post 28. For example, in this embodiment the mounting post 28′may alternatively be positioned further toward the outer end 22 of thecogset 20′ or further toward the hub-facing end 23. In either case themounting post 28′ may further comprise a greater length.

FIG. 9 depicts a cross-sectional view of a cogset and hub assembly 6′.As shown, the cogset 20′ can comprise one or more ratchet teeth. Theratchet teeth can engage with one or more pawls 54 mounted on the hub40′ such that rotation between the hub 40′ and cogset 20′ may beachieved in only one direction. The hub 40′ can be mounted on the shaft36′ by way of hub bearings 31, 32′. As shown, the shaft diameter candecrease in stages. The shaft 36′ can terminate at an end cap 60, 61.

FIG. 10 depicts an exploded view of a cogset 20′. As shown, the cogset20′ can comprise two pieces 25′, 26 attached by cogset spline portions18 to cause co-rotation, as in FIG. 6.

In some embodiments the cogset and hub assemblies 6′ described hereinmay comprise a wide variety of materials, sizes, shapes, and orconfigurations. Because in some embodiments the cogset 20′ can mountdirectly or substantially directly onto the hub 40′ and/or shaft 36′without an intermediary element such as a sprocket carrier, the cogset'sinner diameter can be approximately equal to the outer diameter of thehub 40′ and/or the shaft 36′. Thus, in some embodiments the cog size maybe substantially smaller while mounted on a shaft 36′ compared to priorart cogset and hub assemblies. For example, a cogset and hub assembly 6′mounted on a shaft 36′ may comprise at least one sprocket comprising aninner diameter less than 1%, 2%, 3%, 5%, 7%, 10%, or 15% greater thanthe diameter of the shaft 36′ upon which the cogset and hub assembly 6′is mounted. The cogset 20′ may further be mounted directly orsubstantially directly onto load bearings 35 which similarly mount ontothe hub 40′ and/or shaft 36′.

Further, the shaft 36′ may comprise a portion with a relatively largediameter. For example, a cogset and hub assembly 6′ mounted on a shaft36′ may comprise at least one sprocket comprising an inner diameter lessthan 1%, 2%, 3%, 5%, 7%, 10%, or 15% greater than the diameter of theshaft 36′ corresponding to said sprocket. More generally, the shaft 36′may comprise an average external diameter greater than 1 inch, 1½ inch,1¾ inch, 2 inches, 2¼ inches, 2½ inches, 2¾ inches, 3 inches, 15 mm, 16mm, 17 mm, 18 mm, 19 mm, or 2 cm. Alternatively, the shaft may comprisean external diameter less than 1 inch, ⅞ inch, ¾ inch, ⅝ inch, or ½inch. Further, the shaft may comprise a larger diameter portion 34 withdiameter greater than 125%, 150%, 175%, 200%, 225%, 250%, 275%, or 300%wider than a smaller diameter portion 33 of the shaft 36′ and/or theshaft main body 30′. Alternatively, the shaft may comprise a maximumexternal diameter greater than 1 inch, 1½ inch, 1¾ inch, 2 inches, 2¼inches, 2½ inches, 2¾ inches, or 3 inches. Further, the shaft maycomprise a minimum external diameter less than 1 inch, ⅞ inch, ¾ inch, ⅝inch, ½ inch, ⅜ inch, or ¼ inch. The shaft 36′ may further comprise alighter material such as carbon fiber, aluminum, titanium, plastics, andthe like.

Further, the size of the load bearings 31, 32′, 35 may be altered. Asshown in FIG. 8B, the bearings 31, 32′, 35 can be positioned relativelywide along the axis of the cogset and hub assembly 6′. The load bearings31, 32′, 35 can comprise a bearing diameter of approximately 9/16 inch.Alternatively, the load bearings can comprise a bearing diameter greaterthan 9/16 inch. Further, the balls in the load bearings 31, 32′, 35 maycomprise a bearing diameter less than 1/32 inch, 1/64 inch, 1/128 inch,3/128 inch, 0.8 mm, 0.6 mm, 0.4 mm, or 0.2 mm. Further, the loadbearings 31, 32′, 35 may comprise different sizes. For example, thedriven end hub bearing 32′ can comprise a larger bearing diameter thanthe other bearings 31, 35. Similarly, the driven end hub bearing 32′ canhold balls with diameter smaller than the other bearings 31, 35.

Further, the bearings 31, 32′, 35 and bearing seats 29, 46, 47′ can bepositioned at varying points along the axis of the cogset and hubassembly 6′. For example, the cogset bearings 35 can be positionedwithin 1%, 2%, 3%, 5%, 7%, or 10% of the assembly length L_(A) from thedriven end 100 of the cogset and hub assembly 6. Similarly, the hubbearings 31, 32′ may be positioned within 1%, 2%, 3%, 5%, 7%, or 10% ofthe assembly length L_(A) from the ends 41, 42 of the hub 40′.

Further, the ratchets 54, 55, 27 used may comprise a larger size. Forexample, in FIG. 8B the shaft size may be reduced to allow for a largerratchet. The pawls 54 may be made as large as at least ¼ inches, ½ inch,¾ inch, or 1 inch. The pawls 54 may comprise a lighter material such ascarbon fiber, aluminum, titanium, or the like and still be capable ofbearing the same load due to their increased size. The ratchet mayadditionally comprise a greater number of ratchet teeth per degree ofrotation. Further, the ratchets can, as in preceding discussions,comprise lighter materials, a greater number of teeth per degree ofrotation, and further design changes.

Further, the assembly length L_(A) can be distributed varyingly betweenthe parts of the cogset and hub assembly 6′. For example, the hub 40′can be made shorter or be more substantially overlapped by the cogset20′. Further, the cogset 20′ may be within ¼ inch, ½ inch, ¾ inch, 1inch, 1½ inch, 1¾ inch, 2 inches, 2¼ inches, 2½ inches, 2¾ inches or 3inches of the spokes 9. Further, the axis length L_(A) may be divided,for example, such that the large end cap generally comprises 10%, 20%,30%, or 40% of the axis length, the distance between the flanges 45connecting to the spokes generally comprise 10%, 20%, 30%, 40%, 50%,60%, or 70%, and/or the cogset generally comprises 10%, 20%, 30%, or40%.

Further flexibility can be provided by varying the distance between cogson adjacent sprockets of the cogset 20′. For example, increasing thedistance between cogs on adjacent sprockets can allow a larger chain 4,which may further comprise lighter materials. Alternatively, decreasingthe distance between cogs on adjacent sprockets can allow a greaternumber of sprockets on the cogset 20′. In some embodiments the cogset20′ may comprise greater than 9, 10, 11, 12, 13, 14, or 15 sprockets.

As shown, the alternative embodiments depicted herein may comprisedistinct, equivalent, and altered parts. It will be clear from thedisclosure herein that parts that have only slight differences betweenembodiments may still perform the same function. For example, shafts 36,36′ comprise different shapes but can still perform at least one sharedfunction, namely providing rotational support to the other parts of thecogset and hub assemblies 6, 6′. Further, parts with distinctmorphologies may still perform substantially equivalent functions. Forexample, the ratchet elements of FIGS. 2B, 3B and the ratchet elementsof FIGS. 7B, 8B comprise very distinct parts, but are both capable ofcontrolling the relative rotational properties of the hubs 40, 40′ andcogsets 20, 20′. It will further be clear from the disclosure hereinthat the specific dimensions, cog sizes, and materials attributed to oneembodiment may further be attributable to another embodiment. Forexample, although the shaft 30 in FIG. 2B is different from the shaft30′ in FIG. 7B, it will be clear that the cogset and hub assembly 6 ofFIG. 2B could be modified to accommodate the shaft 30′, while stillmaintaining other differences between the cogset and hub assemblies 6,6′.

Although the foregoing systems and methods have been described in termsof certain preferred embodiments, other embodiments will be apparent tothose of ordinary skill in the art from the disclosure herein.Additionally, other combinations, omissions, substitutions andmodifications will be apparent to the skilled artisan in view of thedisclosure herein. While certain embodiments of the inventions have beendescribed, these embodiments have been presented by way of example only,and are not intended to limit the scope of the inventions. Indeed, thenovel methods and systems described herein may be embodied in a varietyof other forms without departing from the spirit thereof. Accordingly,other combinations, omissions, substitutions and modifications will beapparent to the skilled artisan in view of the disclosure herein.

1. A monoblock cogset comprising: an inner surface comprising aplurality of ratchet teeth; a plurality of cogs; and a portion forreceiving a bearing assembly along said inner surface, wherein thecogset is a monoblock cogset.
 2. The monoblock cogset of claim 1,wherein said inner surface has variable size along the axis of thecogset.
 3. The monoblock cogset of claim 2, wherein said inner surfacegenerally increases in size monotonically from one end to another. 4.The monoblock cogset of claim 3, wherein said cogset includes at leastone cog with cog size less than
 11. 5. The monoblock cogset of claim 1,wherein said cogset is configured to be combined with an additionalcogset.
 6. A cogset assembly comprising: a first monoblock cogsetcomprising: an inner surface comprising a plurality of ratchet teeth;and a plurality of cogs; and a second monoblock cogset comprising aplurality of cogs and being configured to be mounted on said firstmonoblock cogset.
 7. The cogset assembly of claim 6, wherein said firstand second monoblock cogsets are substantially formed from at least twodistinct materials.
 8. The cogset assembly of claim 7, wherein at leastone of said materials is titanium.
 9. A cogset comprising: a pluralityof cogs; an inner surface comprising a spline portion, said innersurface having variable size along the axis of the cogset; and a portionfor receiving a bearing assembly along said inner surface.
 10. Thecogset of claim 9, wherein said inner surface generally increases insize monotonically from one end to another.
 11. The cogset of claim 9,wherein said cogset includes at least one cog with cog size less than11.
 12. The cogset of claim 9, wherein said cogset comprises an outersurface, said outer surface comprising cogs substantially formed from atleast two distinct materials.
 13. The cogset of claim 12, wherein atleast one of said materials is titanium.